diff --git a/litex_boards/partner/platforms/aller.py b/litex_boards/partner/platforms/aller.py
index 9315044..4e0fb62 100644
--- a/litex_boards/partner/platforms/aller.py
+++ b/litex_boards/partner/platforms/aller.py
@@ -105,7 +105,7 @@ _io = [
 
 class Platform(XilinxPlatform):
     default_clk_name = "clk100"
-    default_clk_period = 10.0
+    default_clk_period = 1e9/100e6
 
     def __init__(self):
         XilinxPlatform.__init__(self, "xc7a200t-fbg484-2", _io, toolchain="vivado")
diff --git a/litex_boards/partner/platforms/nereid.py b/litex_boards/partner/platforms/nereid.py
index 53299f6..0494c4c 100644
--- a/litex_boards/partner/platforms/nereid.py
+++ b/litex_boards/partner/platforms/nereid.py
@@ -380,7 +380,7 @@ _connectors = [
 
 class Platform(XilinxPlatform):
     default_clk_name = "clk100"
-    default_clk_period = 10.0
+    default_clk_period = 1e9/100e6
 
     def __init__(self, toolchain="vivado", programmer="xc3sprog"):
         XilinxPlatform.__init__(self, "xc7k160t-fbg676-1", _io, _connectors,
diff --git a/litex_boards/partner/platforms/orangecrab.py b/litex_boards/partner/platforms/orangecrab.py
index 53b36e8..f2c6b09 100644
--- a/litex_boards/partner/platforms/orangecrab.py
+++ b/litex_boards/partner/platforms/orangecrab.py
@@ -56,7 +56,7 @@ _io = [
 
 class Platform(LatticePlatform):
     default_clk_name = "clk48"
-    default_clk_period = int(1e9/48e6)
+    default_clk_period = 1e9/48e6
 
     def __init__(self, **kwargs):
         LatticePlatform.__init__(self, "LFE5U-25F-8MG285C", _io, **kwargs)
diff --git a/litex_boards/partner/platforms/tagus.py b/litex_boards/partner/platforms/tagus.py
index 5e0e658..2c17341 100644
--- a/litex_boards/partner/platforms/tagus.py
+++ b/litex_boards/partner/platforms/tagus.py
@@ -153,7 +153,7 @@ _connectors = [
 
 class Platform(XilinxPlatform):
     default_clk_name = "clk100"
-    default_clk_period = 10.0
+    default_clk_period = 1e9/100e6
 
     def __init__(self):
         XilinxPlatform.__init__(self, "xc7a200t-fbg484-2", _io, _connectors, toolchain="vivado")
diff --git a/litex_boards/partner/platforms/trellisboard.py b/litex_boards/partner/platforms/trellisboard.py
index df74712..99ce16d 100644
--- a/litex_boards/partner/platforms/trellisboard.py
+++ b/litex_boards/partner/platforms/trellisboard.py
@@ -204,7 +204,7 @@ _connectors = [
 
 class Platform(LatticePlatform):
     default_clk_name = "clk12"
-    default_clk_period = 83
+    default_clk_period = 1e9/12e6
 
     def __init__(self, **kwargs):
         LatticePlatform.__init__(self, "LFE5UM5G-85F-8BG756C", _io, _connectors, **kwargs)